The Mean Number-in-System Vector Range for a Multi-Class Queueing Network
B. C. Eaves, P. W. Glynn, and U.G. Rothblum
Mathematics of Operations Research, 182-190 (2004)
In a multiclass network of queues, natural sufficient conditions are given for the mean number-in-system vector to cover the nonnegative orthant as the arrival rate vector varies over the stable domain.